I was aware that the thick wooden spacers were discontinued at some point, maybe 2008. Then Clipper mentioned that he preferred a low position and had the spacers taken from his new car. So his new Morgan may have had spacers added.
Anyway, here are the measurements:
Here is my Roadster with a straight edge across the tunnel and door seal. Note there is no significant gap to the seat base.

And here's Bumble with no spacers:
The gap is a couple of inches!!!!!!!